Chapter 6

Compared to traditional aids like canes, magic books, and talismans, CAD can activate faster, more intricate, and larger-scale magic, symbolizing the superiority of modern magic.

However, it is not necessarily true that CAD is universally superior to traditional aids.

CAD is a precision machine that requires more frequent maintenance and care compared to traditional aids.

The transmission system within it must be calibrated to match the user's thought wave characteristics, which is a particularly important process.

CAD uses the user's thoughts as material (or more appropriately, ink or paint) to output a thought information body called an "activation pattern." The magician, being a good conductor of thoughts, absorbs the activation pattern with their body, using it as a blueprint to construct the magic formula. The activation speed of magic through CAD can vary by 50% to over 100% depending on the quality of the calibration.

Thoughts are said to be particles converted from thoughts or intentions. Each person's thought pattern is unique, with a hundred people having a hundred different patterns, and a thousand people having a thousand different patterns. Each person's thought wave characteristics have subtle differences, and if the CAD is not precisely calibrated, it cannot smoothly exchange thoughts with the user.

There are many other points that can make CAD more user-friendly.

Calibrating CAD is the job of a magic engineer, which is why skilled magic engineers are highly valued.

However, thought wave characteristics change with physical growth and aging, and are also influenced by health conditions, changing daily in a strict sense.

Ideally, CAD should be calibrated daily according to the user's physical condition, but this requires expensive specialized equipment.

Military, police, central government, top research institutions, prestigious schools, or well-funded large corporations can set up CAD calibration facilities and technicians, but small and medium-sized enterprises or individuals generally cannot afford complete self-calibration equipment. Magicians in small organizations typically go to magic machine specialty stores or manufacturer service centers for regular maintenance once or twice a month.

First High School, being a top school, has its own dedicated calibration equipment. Generally, students and faculty members alike have their CADs calibrated at school.

However, for certain special reasons, Da also has the latest CAD calibration equipment at home.

◇◇◇

After dinner, Da, who was adjusting his personal CAD in the basement workshop, turned around at the sound of the only other resident in the house calling him.

"Feel free to come in, I'm just finishing up here."

This was not a lie. And it was likely that Shizuka had timed her call to coincide with a natural break in his work.

"Sorry to bother you. Big brother, I want you to calibrate my CAD..."

She held a CAD that looked like a mobile terminal.

As Shizuka approached, the faint scent of soap wafted through the air.

She was wearing a simple gown, like the ones used for medical examinations.

"Is the setting off?"

This was the attire for rigorous calibration.

"Absolutely not! Big brother's calibration is always perfect."

Shizuka always overpraised him, so Da did not bother to correct her. From past experience, he knew that arguing about such things was a waste of time.

However, since the last comprehensive inspection was only three days ago, and normally there would be a week's interval, Da naturally wondered if there was some sudden reason.

"Only, that..."

"There's no need to be formal with me. Haven't I always said that?"

"Sorry, but I want to change the activation pattern..."

"Oh, I see. You really don't need to be formal with me; otherwise, I'll start worrying."

Da gently tousled his sister's hair and took the CAD from her hand.

Shizuka lowered her head shyly.

"So, what kind of system do you want to add?"

A general-purpose CAD can register up to ninety-nine activation patterns. Even though Shizuka's CAD is the most advanced model and has been further improved, this is still an unbreakable limit.

On the other hand, the types of activation patterns can vary greatly depending on the level of construction of the activation pattern or how much of the magic calculation field the user processes. In practice, there are countless types.

Generally, coordinates, strength, and end conditions are set as variables, and additional processing is done in the magic calculation field. Other elements are pre-set in the activation pattern. However, many people set strength as a constant in the activation pattern to reduce the computational load and speed up the activation of magic. For defensive magic, the relative coordinates centered on the user are often set as constants, and for contact magic, all values are set as constants, as taught in practical classes.

Shizuka, on the other hand, prefers to register activation patterns that minimize the number of constants and increase the flexibility of magic use.

At the age of fifteen, Shizuka already knows far more magic than the average magician. For someone who can skillfully use a wide variety of magic, the limit of ninety-nine is too few.

"I want to add a binding activation pattern... to increase the variety of combat magic."

"Hmm? But I think with your deceleration magic, you don't need to deliberately add binding magic, right?"

Among various spells, Shizuka is particularly skilled in deceleration magic. For example, she can achieve near absolute zero with cooling magic derived from deceleration.

"As you know, deceleration magic is almost always applied to complete individuals, making it difficult to target a single part.

While it's not impossible to achieve partial deceleration or cooling, the activation time is too long.

After today's match, I had an idea.

I think I might be lacking a speed-focused approach to deprive the opponent of their fighting ability with minimal damage."

"Hmm... I don't think that's your style.

Surprising the opponent with speed is indeed a strategy, but given your situation, you can overwhelm them with your extraordinary magic power. The orthodox strategy of performing 'field interference' to nullify the opponent's magic and then attacking with magic that exceeds their defensive capabilities in scale and strength should be more suitable for you."

The "field interference" mentioned here is a technique that incorporates the surrounding space into one's own magic power, making the opponent's magic ineffective. By covering a limited field with a magic that prevents events from changing, it stops the opponent from altering events with magic.

As Da said, Shizuka's field interference ability is very strong. Even when she is on the defensive in a magic battle, she rarely suffers damage from the opponent's magic. If the opponent is Shizuka, the basic strategy of "striking first" in a magic battle cannot be prioritized.

"Can't I?"

However, Da could not say "no" to his sister, who asked so timidly.

"No, it's not that you can't. Yes... if you're in the student council, you might need such magic to deal with other students.

I understand. I'll organize similar activation patterns and try to avoid deleting your existing magic."

Da could not resist his sister's request, but he did not forget to offer advice.

"Actually, you could just carry an extra CAD."

"Only big brother can operate two CADs simultaneously."

"If you have the will, you can do it too."

Shizuka turned her head away, and Da smiled wryly, gently stroking her head. Petting or gently stroking her hair is one of Da's basic ways to please his sister.

The effect was immediate.

The gentle touch of Da's palm covering her head made Shizuka squint her eyes.

"Let's start the measurement process then."

Seeing her mood improve, Da spoke with a technician's expression.

Shizuka, still savoring the touch of his palm, took a step back and gracefully removed the gown.

She revealed a half-naked body that should not be seen by outsiders.

Lying on the measurement table, Shizuka was only wearing a set of white underwear.

This scene transformed the pure white into an incredibly seductive color.

Even as a sister, no, especially because Shizuka is an outstanding beauty, Da could not remain calm. Shizuka exudes a charm that drives men wild.

But even as his sister could not hide her embarrassment, looking at him with moist eyes, Da's eyes showed no emotion.

At that moment, he was a machine for observing, analyzing, and recording the human body.

Without emotion, he perceived the true nature of the situation. At that moment, Da embodied a certain ideal type of magician.

◇◇◇

"Good work, it's finished."

At Da's signal, Shizuka got up from the bed.

This type of measurement cannot be done just anywhere.

Such precise calibration procedures are rare.

For example, the school's calibration facilities involve wearing a headset and placing both hands on a touchpad for measurement.

Shizuka put on the gown she took from Da, who had averted his eyes, and looked at Da's back with a pouting expression.

Da sat on a backless chair, facing the terminal as if nothing had happened.

No, it wasn't "as if nothing had happened."

In fact, nothing had happened, and the same procedure was performed weekly.

If he were to be concerned every time, it would never end.

While he was not immune to embarrassment, he did not let it develop further.

He did not allow it to develop further.

For Shizuka, she was grateful that her brother could remain calm.

—Usually, that is.

"Big brother is so sly..."

"Shizuka?"

Shizuka's coquettish voice raised Da's pitch by an octave.

—A rarely heard, flustered and awkward voice from her brother.

—This voice made her heart race and her body temperature rise. A part of Shizuka felt a strange sense of satisfaction.

Shizuka, still wearing the gown without fastening the front, leaned against Da from behind, their cheeks brushing against each other, her soft breasts pressing against Da's back, and whispered in his ear.

"Even though you leave me with such embarrassing memories, you always remain indifferent..."

"Wait, Shizuka, that...?"

"Or do you not see me as a member of the opposite sex?"

"That would be troublesome!"

This was a reasonable statement. However, the moment this reasonable statement was verbalized, it became a chain that dragged Da's thoughts to a fact he should not be aware of.

"Do you not like me? Do you admire Senpai Nanakusa? Or Senpai Watanabe?

Today, you seemed to chat with them quite intimately..."

"Did you hear that?"

This was impossible.

Shizuka had been in the student council room, learning the operation of the information system from Azusa.

Moreover, if she had been eavesdropping, Da would have noticed.

However, at that moment, he did not have the energy to systematically organize such a rebuttal.

"Of course! After all, those two are beautiful women..."

"Hello? Miss Shizuka? Are you misunderstanding something?"

"Big brother, surrounded by beautiful senpais..."

At some point, Shizuka's left hand was holding her CAD.

"I need to be punished!"

"Ah!"

Shizuka suddenly released a vibration wave, and the helpless Da twitched and fell off the chair.

【Self-repair pattern, automatic activation.】

【Loading core individual information body data from backup system.】

【Loading magic pattern—complete. Self-repair—complete.】

The period of unconsciousness lasted less than a second.

He would not allow himself to lose consciousness for more than an instant.

He would not allow himself to be unconscious for more than an instant.

This was his original magic, akin to a curse.

When he opened his eyes, a beautiful face was peering down at him.

"Good morning, big brother."

"…Did I do something to upset you?"

"Sorry, I went too far with the joke."

Even as she apologized, Shizuka still had a smile on her face.

Her sister, who always maintained a mature attitude, now displayed a cute smile befitting a young girl.

Seeing that smile, everything seemed trivial.

In reality, this was a common playful interaction between siblings.

No matter how intense the means, this sister could never harm him.

"Please spare me..."

Taking Shizuka's extended hand, Da complained with a smile on his face.

◇◇◇

The morning was as usual.

However, compared to usual, today's wake-up felt a bit worse.

His head was a bit fuzzy.

There was no sign of his brother in the house.

He must have gone out for morning training.

This was also as usual.

His brother always went to bed later than her and woke up earlier than her.

The situation where she woke up earlier than him the day before yesterday was very rare.

She had once worried that her brother might be damaging his health.

Now, she understood that this was just unnecessary worry.

Her brother, that person, is special.

The world calls her a genius.

They praise her for being different from others, a special person.

—These people do not understand.

The truly remarkable person, the truly special person, the true genius, is her brother.

That person exists on a different level.

Others know nothing.

The girls who flatter her while hiding their jealousy do not understand.

True unparalleled talent surpasses jealousy and brings fear.

Not reverence, but fear.

Their father, out of fear, subjected his own son to cruel treatment, unfair treatment, and she knew all of this.

His brother believed she did not know.

So, she pretended not to know.

Her father— that man— still attempts to suppress her brother's talent, giving him false setbacks to crush his spirit and break his wings, and she knows all of this.

How absurd.

Originally, he wanted to lock his son in a cell with chains, but he realized his son's talent far exceeded his own.

He provided the means to buy freedom.

The only constraint he had was forced to let go.

The only thing that man could do was to give her brother false titles and take away the world's praise for him.

Knowing that her brother had no interest in such things, he still did it.

…Unable to control her thoughts.

Even feeling as if her own experiences were happening to someone else.

Feeling as if her consciousness was not fully awake.

Was it due to lack of sleep?

Actually, Shizuka knew the reason.

It was because of what happened last night.

At the time, she could maintain a calm attitude.

She even found her flustered brother rare, funny, and cute.

Because that thought overpowered everything.

However, after separating from her brother and lying alone in bed, she could not keep her heart calm.

Her heart raced, and she could not sleep.

Her mind was in turmoil, and she could not rest.

This was love.

However—

It was not romantic love.

It could not be romantic love.

That person is her brother. Since three years ago, Shizuka has been reminding herself of this.

Three years ago, the day she was saved by that person and learned his true value, she vowed to become a sister worthy of that person and has been working hard ever since.

Just as she was once saved by that person, she hopes to one day become his support. She wants to be capable of saving that person, and she still deeply desires this.

She has no demands from that person.

Because the life she should have lost was saved by that person.

Although she is now a chain that binds that person.

She hopes that one day, she can become the key to free that person.

She wants to become his support.

—The immediate task at hand is to prepare breakfast.

Although there will be meals there—

That person will surely return with an empty stomach as usual.

She wants that person to enjoy a delicious breakfast.

This is what she can do now.

Shizuka got up with renewed energy, stretching her arms widely.